MKINITRD(8) BSD System Manager's Manual MKINITRD(8)NAMEmkinitrd — build an initial ramdisk image for use as early userland
SYNOPSISmkinitrd [-b bootdir] [-t tmpdir]
DESCRIPTION
The mkinitrd script builds a ramdisk (md) image based on the UFS filesys‐
tem containing only the most basic tools, such as a minimal init(8),
sh(1) as well as many mount(8) utilities.
It will also copy the contents of /usr/share/initrd onto the ramdisk,
maintaining the same hierarchy.
On completion, the final image will be copied to /boot/kernel/initrd.img,
ready to be used as an early userland. The base directory for
kernel/initrd.img can be changed with the -b option to an optional
bootdir (the default is /boot). The temporary directory to be used for
setting up the image can be specified using the -t option (the default is
/tmp).
The mkinitrd script will check for /etc/defaults/mkinitrd.conf and
/etc/mkinitrd.conf and include the configuration from these files in the
given order, allowing the user to override or add to the following vari‐
ables:
BUILD_DIR
INITRD_SIZE
BIN_TOOLS
SBIN_TOOLS
INITRD_DIRS
CONTENT_DIRS
Adding the following lines to /boot/loader.conf will enable the use of
the created initrd image:
initrd.img_load="YES"
initrd.img_type="md_image"
vfs.root.mountfrom="ufs:md0s0"
The format for vfs.root.realroot in /boot/loader.conf that allows the
user to specify what system to mount as the new root in the initrd is
specified in its general form below:
vfs.root.realroot="<type>:[arg1[:arg2[:argN]]]"
Currently, two types of real root are supported, local and crypt. The
local type allows to mount any local file system that does not require
any special setup apart from the initial discovery and calling the mount
program. The general format is as follows:
vfs.root.realroot="local:<FS TYPE>:<DEVICE PATH>[:<OPTIONS>]"
The crypt type allows to mount volumes supported by cryptsetup. The
device will be set up by prompting the user for his key, and this volume
will then be mounted as the new root.
vfs.root.realroot="crypt:<FS TYPE>:<DEVICE PATH>:<VOLUME NAME>[:<OPTIONS>]"
EXAMPLES
vfs.root.realroot="local:ufs:/dev/vg00/lv0[:OPTIONS]"
vfs.root.realroot="crypt:ufs:/dev/ad0s0a:secvolume[:OPTIONS]"
SEE ALSOmd(4), loader.conf(5)HISTORY
The mkinitrd command first appeared in DragonFly 2.7.
AUTHORSmkinitrd was written by Alex Hornung ⟨ahornung@gmail.com⟩.
BSD November 3, 2010 BSD